Bearing unit with retaining cage

Abstract

A bearing unit having at least one row of rolling bodies; and at least one cage for retaining a respective one of the at least one row of rolling bodies. The at least one cage comprising at least one base bar, a plurality of arms circumferentially spaced apart and extending from one side of the base bar, and a plurality of partially spherical cavities for retaining the respective one of the at least one row of rolling bodies. The respective row of rolling bodies and the at least one cage are in contact with each other along contact points positioned near a polar region of the respective one of the at least one row of rolling bodies, so that an angular distance (α) of the contact points with respect to an equator of the respective one of the at least one row of rolling bodies is between 40° and 75°.

What is claimed is: 
     
       1. A bearing unit comprising:
 at least one row of rolling bodies; and 
 at least one cage for retaining a respective one of the at least one row of rolling bodies, the at least one cage comprising at least one base bar; a plurality of arms circumferentially spaced apart and extending from one side of the base bar; and a plurality of partially spherical cavities for retaining the respective one of the at least one row of rolling bodies, 
 wherein the respective one of the at least one row of rolling bodies and the at least one cage are in contact with each other along contact points positioned near a polar region of the respective one of the at least one row of rolling bodies, so that an angular distance (α) of the contact points with respect to an equator of the respective one of the at least one row of rolling bodies is between 40° and 75°. 
 
     
     
       2. The bearing unit of  claim 1 , wherein the contact points between the respective one of the at least one row of rolling bodies and the at least one cage consist of bumps, the bumps are radially outward facing bumps and radially inward facing bumps, the bumps are formed in the partially spherical cavities of the at least one cage and extend radially towards an inside of the partially spherical cavities. 
     
     
       3. The bearing unit of  claim 2 , wherein the radially outward facing bumps are symmetrical with respect to a rotation axis (Y) of the respective one of the at least one row of rolling bodies, and have an angular position measured by an angle (α′) between the rotation axis (Y) and a distal edge (D′) of a respective one of the radially outward facing bump) with respect to the rotation axis (Y), the rotation axis (Y) is in a range between 15° and 50°. 
     
     
       4. The bearing unit of  claim 2 , wherein the radially inward facing bumps are symmetrical with respect to a rotation axis (Y) of the respective one of the at least one row of rolling bodies, and have an angular position measured by an angle (α″) between the rotation axis (Y) and a distal edge (D″) of the radially inward facing bump with respect to the rotation axis (Y), the rotation axis (Y) is in a range between 15° and 45°. 
     
     
       5. The bearing unit of  claim 2 , wherein
 the outward facing bumps include an angular extension of fifteen degrees (15°), and 
 the inward facing bumps include an angular extension of fifteen degrees (15°). 
 
     
     
       6. The bearing unit of  claim 2 , wherein the bumps and edges of a spherical surface are spaced apart by a distance of 0.15 mm (millimeter) and 3 mm, the spherical surface delimits the partially spherical cavity. 
     
     
       7. The bearing unit of  claim 6 , wherein a thickness of the bumps with respect to the spherical surface has a value of between 0.05 mm and 0.5 mm. 
     
     
       8. The bearing unit  claim 6 , wherein a difference between diameter of the spherical surface and diameter of the respective one of the at least one row of rolling bodies inserted inside the partially spherical cavity is less than 2.5 mm. 
     
     
       9. The bearing unit of  claim 1 , wherein the a respective one of the plurality of partially spherical cavities comprises chords, the chords form inlet edges of a lower end for retaining respective one of the at least one row of rolling bodies, the chords comprise a length having a value between the diameter of the respective one of the at least one row of rolling bodies and the diameter of the respective one of the at least one row of rolling bodies reduced by 3 mm. 
     
     
       10. A wheel hub assembly for motor vehicles, comprising:
 a hub; and 
 a bearing unit comprising,
 a radially outer ring provided with a respective radially outer raceway, 
 at least one radially inner ring provided with a respective radially inner raceway, 
 at least one row of rolling bodies between the radially outer ring and the at least one radially inner ring, and 
 at least one cage for retaining the at least one row of rolling bodies; 
 wherein the at least one cage is configured for retaining a respective one of the at least one row of rolling bodies; 
 wherein the at least one cage comprises a plurality of arms circumferentially spaced apart and extending from one side of a base bar, the cage defining partially spherical cavities for retaining the respective one of the at least one row of rolling bodies; 
 wherein the partially spherical cavities comprise chords; 
 wherein the chords form inlet edges of a lower end for retaining respective one of the at least one row of rolling bodies; 
 wherein the chords further comprise a length having a value between the diameter of the respective one of the at least one row of rolling bodies and the diameter of the respective one of the at least one row of rolling bodies reduced by 3 mm. 
 
 
     
     
       11. A wheel hub assembly for motor vehicles, comprising:
 a hub; and 
 a bearing unit comprising,
 a radially outer ring provided with a respective radially outer raceway, 
 at least one radially inner ring provided with a respective radially inner raceway, 
 at least one row of rolling bodies between the radially outer ring and the at least one radially inner ring, and 
 
 at least one cage for retaining the at least one row of rolling bodies, 
 wherein a respective one of the at least one row of rolling bodies and the at least one cage are in contact with each other along contact points positioned near a polar region of the respective one of the at least one row of rolling bodies, so that an angular distance (α) of the contact points with respect to an equator of the respective one of the at least one row of rolling bodies is between 40° and 75°. 
 
     
     
       12. The wheel hub assembly for motor vehicles of  claim 11 ,
 wherein the contact points between the respective one of the at least one row of rolling bodies and the at least one cage consist of bumps, the bumps are radially outward facing bumps and radially inward facing bumps, the bumps are formed in the partially spherical cavities of the at least one cage and extend radially towards an inside of the partially spherical cavities; 
 wherein the outward facing bumps include an angular extension of fifteen degrees (15°), and the inward facing bumps include an angular extension of fifteen degrees (15°). 
 
     
     
       13. The wheel hub assembly for motor vehicles of  claim 12 , wherein the bumps and edges of a spherical surface are spaced apart by a distance of 0.15 mm (millimeter) and 3 mm, the spherical surface delimits the partially spherical cavity. 
     
     
       14. The bearing unit of  claim 13 , wherein thickness of the bumps with respect to the spherical surface has a value of between 0.05 mm and 0.5 mm. 
     
     
       15. A bearing unit comprising:
 at least one row of rolling bodies; and 
 at least one cage for retaining a respective one of the at least one row of rolling bodies, the at least one cage comprising at least one base bar a plurality of arms circumferentially spaced apart and extending from one side of the base bar; and a plurality of partially spherical cavities for retaining the respective one of the at least one row of rolling bodies, 
 wherein the respective one of the at least one row of rolling bodies and the at least one cage are in contact with each other along contact points positioned near a polar region of the respective one of the at least one row of rolling bodies, so that an angular distance (a) of the contact points with respect to an equator of the respective one of the at least one row of rolling bodies is between 40° and 75°, 
 wherein the contact points between the respective one of the at least one row of rolling bodies and the at least one cage consist of bumps, the bumps are radially outward facing bumps and radially inward facing bumps, the bumps are formed in the partially spherical cavities of the at least one cage and extend radially towards an inside of the partially spherical cavities, 
 wherein the bumps and edges of a spherical surface are spaced apart by a distance of 0.15 mm (millimeter) and 3 mm, the spherical surface delimits at least one of the partially spherical cavities, 
 wherein thickness of the bumps with respect to the spherical surface has a value of between 0.05 mm and 0.5 mm, and 
 wherein difference between diameter of the spherical surface and diameter of the respective one of the at least one row of rolling bodies inserted inside the partially spherical cavity is less than 2.5 mm.